Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from corsica.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Thu, 20 Jul 89 03:17:49 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 20 Jul 89 03:17:42 -0400 (EDT) Subject: SPACE Digest V9 #543 SPACE Digest Volume 9 : Issue 543 Today's Topics: Re: Don't mess with NASA? Re: space news from May 15 AW&ST (replacing computers) Re: Don't mess with NASA? Re: Don't mess with NASA? Re: HR2674: Dear Space Activist Re: Two Questions Re: Apollo Re: Don't mess with NASA (afterburners) Re: Space station computers Re: SPACE Digest V9 #535 Re: Don't mess with NASA (afterburners) Voyager Status for 07/05/89 (Forwarded) Space program on PBS-TV in July. ---------------------------------------------------------------------- Date: 4 Jul 89 15:01:15 GMT From: mcvax!ukc!stl!stc!pete@uunet.uu.net (Peter Kendell) Subject: Re: Don't mess with NASA? From article <1989Jul2.211254.15469@utzoo.uucp>, by henry@utzoo.uucp (Henry Spencer): } } Actually, you can find non-government birds with afterburners, but there } aren't very many of them and often they aren't very accessible. What about Concorde? Just the price of a British Airways or (perhaps preferably) Air France ticket. } $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology } (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ^^^^^^^^^^^^^ Please explain! -- ---------------------------------------------------------------------------- | Peter Kendell | | ...{uunet!}mcvax!ukc!stc!pete | ---------------------------------------------------------------------------- ------------------------------ Date: 4 Jul 89 15:43:06 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: space news from May 15 AW&ST (replacing computers) In article <11749@ulysses.homer.nj.att.com> smb@ulysses.homer.nj.att.com (Steven M. Bellovin) writes: >> The real botch here is that the computers are so inaccessible that it takes >> four hours to replace one. > >Sorry, I don't necessarily agree. As Henry obviously knows, design of >something like a space shuttle is a series of tradeoffs... Granted... but NASA has somewhat of a history of assuming that the hardware must work -- it says so in The Book, after all! -- and so it's unnecessary to set things up so the astronauts can fix it. I.e., while tradeoffs do happen, they can and do get skewed by institutional biases. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 4 Jul 89 06:53:08 GMT From: alpha!wxh@lanl.gov (Billy Harvey) Subject: Re: Don't mess with NASA? In article <1989Jul2.211254.15469@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > In article shafer@drynix.dfrf.nasa.gov writes: > >>... If you want class when climbing into an aircraft, it has to have > >>afterburners. > > > >Better watch it, Henry--you'd have to do it in a government-sponsored, > >government-funded aircraft! :-) :-) > > Ouch. Touche. :-) Theres a saying military pilots have - "Just remember, what you're flying was built by the lowest bidder!" Billy Harvey wxh@a.lanl.gov ------------------------------ Date: 4 Jul 89 20:08:51 GMT From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Don't mess with NASA? In article <1989Jul4.153845.19465@utzoo.uucp> I wrote: >>>Actually, you can find non-government birds with afterburners, but there >>>aren't very many of them and often they aren't very accessible. >> >> [F-20] ...What others are there? > >I know of two others which used to exist... And of course, I forgot about Concorde. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 4 Jul 89 16:08:01 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: HR2674: Dear Space Activist In article <25978@agate.BERKELEY.EDU> web@garnet.berkeley.edu (William Baxter) writes: >Here is Ron Packard's letter to Space Activists. Are you one? This >bill needs more Cosponsors. Have you seen your Representative about >HR2674? I too would urge US readers to get off their behinds and ask their Congressthing whether he/she/it supports this, and if not why not. This bill looks like a very good thing. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Wed, 5 Jul 89 01:12:04 -0500 From: avr@cs.purdue.edu (Andrew V. Royappa) Please remove me from this list. Thanks, Andrew Royappa ------------------------------ Date: 5 Jul 89 04:20:40 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: Two Questions In article <101270024@hpcvlx.HP.COM> gvg@hpcvlx.HP.COM (Greg Goebel) writes: > 1: A recent AEROSPACE AMERICA article discussed nuclear propulsion > and kept referring to "specific impulse", measured in seconds? > Can anyone please define? It's a peculiar and somewhat archaic but still widespread way of measuring exhaust velocity. It's thrust*time/fuelweight, and the units happen to be seconds because of the peculiar notion of measuring fuel burn by weight rather than mass. It turns out to be exhaustvelocity/g, where g is the acceleration of gravity, 9.81 m/s^2. Exhaust velocity is the fundamental measure of rocket engine performance; via conservation of momentum, it determines how much boost you get out of each kg of fuel. (Okay, for the curious... For a pure rocket, carrying its fuel with it, integration of the differential equation of momentum conservation gives us velocitychange = exhaustvelocity * ln(massbefore/massafter) as the basic rocket equation. Note the natural logarithm; what this says is that it's very hard to get velocity changes more than a few times the exhaust velocity. Hence the importance of high exhaust velocity.) > 2: Mr. Spencer (being the usual gold mine of information that he is) > made reference to Giotto being reactivated. What is the current > operational capability of Giotto? I thought it had been damaged > somewhat by the Halley flyby (but "Ah could be wrong!") Giotto is thought to be somewhat damaged, but also thought to be working well enough for another comet encounter to be useful. We won't know for sure until the revival attempt is made and tests are run. Last I heard, the external mirror assembly for the camera is thought to be completely gone [!], which probably means no pictures. But most of the other science instruments should still be okay. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Wed, 5 Jul 1989 12:35-EDT From: Dale.Amon@H.GP.CS.CMU.EDU Subject: Re: Apollo > follow-ons. (Anyone who claims that Apollo was always meant to be a > one-shot has never seen some of the work Apollo did on follow-ons to the > early missions. Apollo was strangled in infancy.) Again, Henry... I agree that the engineers had lots of pretty pictures and pipe dreams of what wondrous things they were going to do after Apollo. BUT... I do not believe that the politicians EVER had any such ideas. Apollo was politically motivated, had a clearly defined goal, and was disassembled as soon as the goal was reached and sucked dry of political profit. That was inherent in the project from it's inception. ------------------------------ Date: 6 Jul 89 02:28:47 GMT From: bobmon@iuvax.cs.indiana.edu (RAMontante) Subject: Re: Don't mess with NASA (afterburners) shafer@drynix.dfrf.nasa.gov : - -Attractive though it may be, Concorde won't leave any modern western -fighters standing. Top speed may be greater than some fighters, but -they'll beat it `off the line'. (Do you have drag racing in the U K?) Does this disqualify it as a `B-2' bomber? I can't see too many big planes standing on their tails at the end of the runway, even without a bomb load... Sure, let's drop truffles and champagne on the Warsaw Pact forces. That should *really* demoralize 'em! [In a desperate attempt to get relevant again...] I *personally* think that a "classy ride" is one that can't use aerodynamic control surfaces. ------------------------------ Date: Wed, 5 Jul 1989 12:17-EDT From: Dale.Amon@H.GP.CS.CMU.EDU Subject: Re: Space station computers > There are reasons, quite apart from technical feasibility, why touch > screens and voice input have never been terribly popular except for > specialized applications. Ah, Henry. I think we are in disagreement on this one. I've spent the last 4 years doing gesture research and I really think you are wrong. But this is not the place to go into the details of the technology I am discussing. It is NOT a touch screen. Some of the work was supported by NASA SBIR's to a local company subcontracted to the CMU Computer Music Lab. I think one of the reason's is that there is interest in non-mouse techniques of direct manipulation that do not require getting dressed (gloved, visored) for the computer. Fingers do not require gravity for operation. I could go into many other reasons for the advantages of direct manipulation. Using a mouse is like having 9 out of 10 fingers cut off. And on the issue of resolution, I will hold my ground. I have discussed the issue with an archivists and find agreement. I have heard of even MORE severe requirements for the arts, particular the storage of etchings with very fine line width modulation. The feel of the art CANNOT be conveyed without DPI resolutions far, far in excess of any I have suggested. Yes, you can zoom in on areas. But you lose the essence of the whole picture. Show me an art work original, and show me the piece at 120 DPI and guarantee you I will see an overwhelming difference. And if 400 DPI were enough, then typesetters wouldn't bother with the expensive equipment for printing books. They'd just use your laserwriter output. 120 DPI might seem miraculous to a long time computer user. But archivists, artists, and people used to "analog" media are not impressed by it. ------------------------------ Date: Wed, 5 Jul 1989 12:46-EDT From: Dale.Amon@H.GP.CS.CMU.EDU Subject: Re: SPACE Digest V9 #535 > I also believe that Ada was originally conceived as a high-water mark in > DSD and DASD design, and the OOD support comes, as for OOD itself, as an > evolution from these techniques. Object Oriented Design comes from Smalltalk, not NASA or DOD. Let's keep our spinoff claims honest... > Of course, I'm somewhat biased, as I was converted from PL/M to Ada for > system implementation purposes, and the system that I'm doing Ada on > has OS NO WONDER YOU LIKE ADA. I wrote about 20K lines or so of PL/I about 15 years ago. It is the most GAWDAWFUL language I ever had the misfortune to deal with. (The most telling statement in one of the IBM manuals was a place that made the statement, "In this case PL/I will probably...") Personally I'd rather use Objective-C or an object oriented LISP with the ability to link in routines written in other languages. I've done a fair amount of NASA SBIR work using such techniques. I would NOT encourage any company I was involved in to go for on board station software though, because I find ADA to be of little use in the real market place. I would state again, that in my opinion, ADA is not an object oriented language. It is a very large complex language that has enough different sets of features that one can FAKE many of the techniques of object oriented programming. It does not, to my knowledge, have Classes, Class inheritance (single OR multiple), Class and Object Methods. I'd love to see a sample of the ADA standard syntax for sending a message to an object to execute a method on an argument list of optional length... ------------------------------ Date: 5 Jul 89 10:27:49 GMT From: mcvax!ukc!stl!stc!praxis!hilbert!macey@uunet.uu.net (Ian Macey) Subject: Re: Don't mess with NASA (afterburners) In article <700@flada.tcom.stc.co.uk> pete@tcom.stc.co.uk (P. Kendell) writes: >From <1989Jul2.211254.15469@utzoo.uucp>, by henry@utzoo.uucp (H. Spencer): >} >} Actually, you can find non-government birds with afterburners, but there >} aren't very many of them and often they aren't very accessible. > > What about Concorde? Just the price of a British Airways or Nope, Concorde doesn't use afterburners. But then again it doesn't need to to leave most fighters standing. Hey! How about putting a bomb bay in a Concorde and calling it a B2? (could have saved the US government millions!!! :-) Ian. |\\\X\\|\ | Ian Macey Bath, England. (macey@praxis.co.uk) |\\X\\\|\\ | ---------------------------------------------------------------- |\X\\\\|\\\| " there are never no bugs, only bugs you haven't found " ------------------------------ Date: 6 Jul 89 00:42:13 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Voyager Status for 07/05/89 (Forwarded) Voyager Status Report July 5, 1989 Voyager 2's television cameras this week remained the only experiment on the spacecraft to detect Neptune, a fact that does not surprise Voyager scientists who anticipate that many of the experiments will not "see" the Neptunian system until a month or even days before the spacecraft's closest approach. The planetary radio astronomy (PRA) experiment, which detects radio-wave emissions from planets, has not yet "heard" Neptune. But interestingly, the instrument is still hearing radio emissions from Jupiter which, next to the Sun, is the noisiest radio source in the solar system. This Friday, the heating unit for the 20-inch mirror in the infrared interferometer and spectrometer (IRIS) will be turned off to allow the heat-mapping instrument to cool down to its approximately 0 degree Celsius (32 degree Fahrenheit) operating temperature. When the IRIS is not making observations, the heater is kept on to preserve the instrument's sensitivity. A 1 1/2-month cool-down period will ensure the IRIS is ready for its most critical observations of heat emissions from Neptune and Triton beginning about 10 days prior to Voyager 2's closest approach to the planet. DISTANCE FROM EARTH: 2,670,438,000 miles DISTANCE FROM NEPTUNE: 45,495,000 miles HELIOCENTRIC VELOCITY: 42,202 mph ------------------------------ Date: 5 Jul 89 19:30:00 GMT From: wrksys.dec.com!klaes@decwrl.pa.dec.com (CUP/ASG, MLO5-2/G1 6A, 223-3283) Subject: Space program on PBS-TV in July. There will be a two-part program on Public Broadcasting Service (PBS-TV) this month, titled "The Other Space Race". The first part (July 16) examines the space technology of China and Japan, concentrating on communications, weather, and remote-sensing technology. The second part (July 23) examines space programs underway in Europe. You will have to check your local listings for times. These programs are part of a series called INNOVATION. Source: SCIENCE NEWS, June 24, 1989. Larry Klaes klaes@renoir.dec.com or - ...!decwrl!renoir.dec.com!klaes or - klaes%renoir.dec@decwrl.dec.com N = R*fgfpneflfifaL ------------------------------ End of SPACE Digest V9 #543 *******************